Pyfakefs 5.7.2 regression for NamedTemporaryFile

[cal-pratt]

Describe the bug
It seems that pause/resume functionallity somehow causes NamedTemporaryFile to be double deleted, leading to test failures. This happens in pyfakefs==5.7.2 but not pyfakefs==5.7.1.

How To Reproduce
Example test:

from tempfile import NamedTemporaryFile


def test(fs):
    fs.pause()
    fs.resume()
    with NamedTemporaryFile() as f:
        pass

With crash that looks like this:

$ pytest test.py
============================= test session starts ==============================
platform darwin -- Python 3.11.10, pytest-8.3.3, pluggy-1.5.0
rootdir: 
configfile: pyproject.toml
plugins: pyfakefs-5.7.2, ...
collected 1 item

test.py F                                                                [100%]

=================================== FAILURES ===================================
_____________________________________ test _____________________________________

fs = <pyfakefs.fake_filesystem.FakeFilesystem object at 0x1129c02d0>

    def test(fs):
        fs.pause()
        fs.resume()
>       with NamedTemporaryFile() as f:

.../test.py:7: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
.../3.11/lib/python3.11/tempfile.py:519: in __exit__
    self.close()
.../3.11/lib/python3.11/tempfile.py:526: in close
    self._closer.close()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <tempfile._TemporaryFileCloser object at 0x112982290>
unlink = <built-in function unlink>

    def close(self, unlink=_os.unlink):
        if not self.close_called and self.file is not None:
            self.close_called = True
            try:
                self.file.close()
            finally:
                if self.delete:
>                   unlink(self.name)
E                   FileNotFoundError: [Errno 2] No such file or directory: '/var/folders/41/ptjvny1d7tsbn59t_ywv2y2m0000gq/T/tmpzytjbc5o'

.../3.11/lib/python3.11/tempfile.py:463: FileNotFoundError
=========================== short test summary info ============================
FAILED test.py::test - FileNotFoundError: [Errno 2] No such file or directory...
============================== 1 failed in 0.53s ===============================

Your environment

macOS-14.7.1-arm64-arm-64bit
Python 3.11.10 (main, Sep  7 2024, 01:03:31) [Clang 15.0.0 (clang-1500.3.9.4)]
pyfakefs 5.7.2
pytest 8.3.3

Note, I can also reproduce this on a linux VM.

[mrbean-bremen]

Thanks! I will see if I can fix this or revert the related change (this was a performance improvement, not a fix or feature, so it would have no further impact). Obviously missing some tests here...

[mrbean-bremen]

For the record: I can confirm that the problem happens with Python 3.10 and 3.11, but not with 3.12 and 3.13 (tested under WSL). Under Windows it obviously doesn't happen, as the code in question is POSIX-specific (as was the change that broke it).

[mrbean-bremen]

Should be fixed in main branch now - can you please check? If it works for you, I will make another patch release.

[cal-pratt]

Nice I will try this out today and get back to you!

[cal-pratt]

Retested against a clone of origin/main installed. All looks good!
Thanks for getting to this so quickly! 😄

[mrbean-bremen]

Thanks for reporting!

[mrbean-bremen]

FYI: Just made a patch release with the fix. I was waiting for feedback for another fix, but decided to go ahead without that.